RE: should one use ANSI join syntax when writing an Oracle applic ation?
- From: "Ken Naim" <kennaim@xxxxxxxxx>
- To: <Brandon.Allen@xxxxxxxxxxx>, <paul.baumgartel@xxxxxxxxxxxxxxxxx>, <breitliw@xxxxxxxxxxxxx>, <Jacques.Kilchoer@xxxxxxxxx>
- Date: Thu, 19 Oct 2006 16:12:54 -0500
Well, I know for a fact that this is the case in 10g as it happened to me
just the other day. I had a situation where a.x=b.x and a.x in
('a','b','c',.... etc.) and the optimizer choose to use an index on b.x
Ken
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Allen, Brandon
Sent: Thursday, October 19, 2006 11:50 AM
To: paul.baumgartel@xxxxxxxxxxxxxxxxx; breitliw@xxxxxxxxxxxxx;
Jacques.Kilchoer@xxxxxxxxx
Cc: oracle-l
Subject: RE: should one use ANSI join syntax when writing an Oracle applic
ation?
I thought Oracle was smart enough to perform transitive closure on its
own even if you don't explicitly write it in your SQL, e.g. Metalink
#68979.1:
"Transitivity and Transitive Closure
===================================
Purpose
~~~~~~~
This article explains how the Cost Based Optimizer (CBO) generates
transitive
predicates to open potential new access methods."
> -----Original Message-----
> From: oracle-l-bounce@xxxxxxxxxxxxx
> [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Baumgartel, Paul
> Wolfgang,
>
> Just to confirm, your point is that adding
> the (logically unnecessary) "and A.x = C.x" provides more
> information that the optimizer can use to choose a more
> efficient access path?
>
>
>
> -----Original Message-----
> From: oracle-l-bounce@xxxxxxxxxxxxx
> [mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of Wolfgang Breitling
>
> I need some help here. How do I code a full transitive
> closure join with the new syntax? In the traditional syntax I can say:
>
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